Ryan Dow scored twice as Dundee United knocked in three goals inside 10 first-half minutes at Stranraer to reach the last eight in the Scottish Cup.

The League One leaders were no match for last year's beaten finalists as Chris Erskine raced through to score.

Dow then clipped in a composed finish, leaving a trail of defenders in his wake, and he rounded home goalkeeper David Mitchell soon after.

Stranraer battled on valiantly but rarely threatened the visitors' goal.

United reached the League Cup final last weekend, although there was to be a bitter aftertaste for supporters, with Stuart Armstrong and Gary Mackay-Steven sold to Celtic on transfer deadline day.

However, Erskine and Dow proved more than adequate replacements in midfield as Jackie McNamara's side brushed aside their part-time opponents.

Dow, so impressive as a substitute in the Hampden win over Aberdeen, was full of clever running and kept a cool head to take his goal tally for the season to five.

Erskine celebrated his birthday with the opening strike, capitalising on an error from the hosts on 21 minutes.

Sean Winter was slack with a pass to Scott Rumsby, with the defender caught on his heels, allowing Erskine to sprint clear and prod the ball through the legs of advancing Mitchell.

Stranraer were almost given an unlikely helping hand when Callum Morris crashed a header towards his own goal at a corner and keeper Radoslaw Cierzniak made a smart reaction save to bail out his team-mate.

Cierzniak was unconvincing in dealing with crosses but the Blues found themselves further behind before they could put the Pole under any more pressure.

It was a comfortable afternoon for last year's beaten Scottish Cup finalists

Rumbsy was guilty of diving into a challenge on left edge of penalty box allowing Dow to cut inside, drift past Frank McKeown and cleverly lift the ball over the diving Mitchell.

The third goal followed almost immediately with Nadir Ciftci slipping the ball through the legs of Grant Gallagher near the centre spot before threading a wonderful pass for Dow to run on to and the midfielder rounded Mitchell to double his tally.

Another corner had United in a spot of bother before half-time when McKeown beat Cierzniak to the delivery but his looping header was nodded over by defender Ryan McGowan.

Stranraer gamely plugged away in the second half and Cierzniak held on to a fizzing Chris Aitken free-kick, while Gallagher's curling shot was not too far away from finding the top corner.

But it was United who came closest to adding another goal when substitute Telfer's stoppage-time free-kick was tipped over by the fingertips of Mitchell.